It could be that you are working for a very healthy organization where having a quick call is no big deal as they don't happen that frequently. In that context, you are entirely right. If all the quick calls are just that, quick calls from direct team members then this entire article does not apply to you.
However, there are many, many, many (really a lot) of organizations out there that are in various degrees but continuous state of chaos. Things like constantly shifting deadlines, goals changing, roles being poorly defined and various other things.
The sort of company where anyone who cares about their work will find themselves in a boiling frog type of scenario if they are not careful. They try to take up extra work that is not technically part of their role description, or simply by being knowledgeable attract attention.
In those companies where everyone is a continuous state of mild panic it isn't just one "quick call" it is a steady stream of them, interrupted by unannounced actual calls. Or, if you are in the office, people constantly walking by and "quickly" asking for things.
Certainly, when you find yourself in a situation where the documentation is always lacking. If you then make the mistake of writing the few pieces of documentation that actually are useful you suddenly might find yourself in the position of "knowledge holder" where everyone flocks to for their questions. In companies like this knowledge holders then get over asked (with questions often covered in the documentation), making it difficult for them to focus on their work.
In that sort of situation you need to be competent at setting boundaries as companies will often not do that for you. They happily take advantage of someone running 100% of the time, so they don't need the expense of another FTE added to payroll. Or if I'd have to do a slightly less cynical take, because they simply do not realize they are missing an FTE. Or, to go back to a more cynical take, they are filling roles with seat warmers instead of competency.
In a previous organization, I have had to actively enforce what the article suggests and more. Even then I eventually decided to leave as I simply couldn't see a path forward with the company getting their structure in order in time and me keeping my sanity.
A few of the things I started doing (some overlap with the article):
- Set my teams status with a message encouraging people to ask the question, not just greed me. Eventually, I did include a link to one of the "no hello" websites. I think https://nohello.net/en/
- Refuse unannounced teams calls from most people except a few people. I'd hang up and just leave a message along the lines of "hi, bit busy with something at the moment, what was it you are trying to reach me about?".
- Decline meetings without a clear agenda.
- Decline meetings with a clear agenda, but where I was simply not needed. Sometimes it was not related to my responsibilities, I would let them know and if I could, I would forward the meeting to a person that was responsible. In other cases, I simply was not needed in person because the information was already written down somewhere. In that case I'd provide them with the information.
- Decline meetings during my lunch break.
- Decline meetings that overlapped with other meetings in my agenda, specifically stating I was not available due to another meeting.
- Block a few moments in the week in my agenda as "focus time", set those to private meetings. To the credit of the company, they eventually did recognize that a lot of the IT engineering staff was sitting in too many meetings and then as a company policy blocked of two afternoons for everyone as focus time.
- When getting general help requests about things I knew for a fact were written down in documentation, I'd refer them there first. Ask them to go over the documentation first and then let me know if they had specific questions.
To be fair, this was an extremely chaotic and continually panicked company, with a lot of extra things compounding all of this. But it isn't that rare either as I know plenty of people who actually burned out over similar things at various different companies.